cross-libraries optimization in Scala 2.12

_Main.scala

object Main {
  val xs = (1 to 10).toList

  def simple(): List[Int] =
    xs.map { i =>
      i + 1
    }
}

default.txt

Compiled from "Main.scala"
public final class Main$ {
  public static Main$ MODULE$;

  public static {};
    Code:
       0: new           #2                  // class Main$
       3: invokespecial #25                 // Method "<init>":()V
       6: return

  public scala.collection.immutable.List<java.lang.Object> xs();
    Code:
       0: aload_0
       1: getfield      #28                 // Field xs:Lscala/collection/immutable/List;
       4: areturn

  public scala.collection.immutable.List<java.lang.Object> simple();
    Code:
       0: aload_0
       1: invokevirtual #32                 // Method xs:()Lscala/collection/immutable/List;
       4: invokedynamic #53,  0             // InvokeDynamic #0:apply$mcII$sp:()Lscala/runtime/java8/JFunction1$mcII$sp;
       9: getstatic     #58                 // Field scala/collection/immutable/List$.MODULE$:Lscala/collection/immutable/List$;
      12: invokevirtual #62                 // Method scala/collection/immutable/List$.canBuildFrom:()Lscala/collection/generic/CanBuildFrom;
      15: invokevirtual #68                 // Method scala/collection/immutable/List.map:(Lscala/Function1;Lscala/collection/generic/CanBuildFrom;)Ljava/lang/Object;
      18: checkcast     #64                 // class scala/collection/immutable/List
      21: areturn

  public static final int $anonfun$simple$1(int);
    Code:
       0: iload_0
       1: iconst_1
       2: iadd
       3: ireturn
}

opt:l:classpath.txt

Compiled from "Main.scala"
public final class Main$ {
  public static Main$ MODULE$;

  public static {};
    Code:
       0: new           #2                  // class Main$
       3: invokespecial #30                 // Method "<init>":()V
       6: return

  public scala.collection.immutable.List<java.lang.Object> xs();
    Code:
       0: aload_0
       1: getfield      #33                 // Field xs:Lscala/collection/immutable/List;
       4: areturn

  public scala.collection.immutable.List<java.lang.Object> simple();
    Code:
       0: aload_0
       1: invokevirtual #37                 // Method xs:()Lscala/collection/immutable/List;
       4: invokedynamic #58,  0             // InvokeDynamic #0:apply$mcII$sp:()Lscala/runtime/java8/JFunction1$mcII$sp;
       9: getstatic     #63                 // Field scala/collection/immutable/List$.MODULE$:Lscala/collection/immutable/List$;
      12: invokevirtual #67                 // Method scala/collection/immutable/List$.canBuildFrom:()Lscala/collection/generic/CanBuildFrom;
      15: astore_3
      16: astore_2
      17: dup
      18: ifnonnull     23
      21: aconst_null
      22: athrow
      23: astore_1
      24: aload_3
      25: getstatic     #63                 // Field scala/collection/immutable/List$.MODULE$:Lscala/collection/immutable/List$;
      28: invokevirtual #71                 // Method scala/collection/immutable/List$.ReusableCBF:()Lscala/collection/generic/GenTraversableFactory$GenericCanBuildFrom;
      31: if_acmpne     152
      34: aload_1
      35: getstatic     #76                 // Field scala/collection/immutable/Nil$.MODULE$:Lscala/collection/immutable/Nil$;
      38: if_acmpne     49
      41: getstatic     #76                 // Field scala/collection/immutable/Nil$.MODULE$:Lscala/collection/immutable/Nil$;
      44: astore        8
      46: goto          160
      49: new           #78                 // class scala/collection/immutable/$colon$colon
      52: dup
      53: aload_1
      54: invokevirtual #84                 // Method scala/collection/immutable/List.head:()Ljava/lang/Object;
      57: invokestatic  #90                 // Method scala/runtime/BoxesRunTime.unboxToInt:(Ljava/lang/Object;)I
      60: invokestatic  #49                 // Method $anonfun$simple$1:(I)I
      63: invokestatic  #94                 // Method scala/runtime/BoxesRunTime.boxToInteger:(I)Ljava/lang/Integer;
      66: getstatic     #76                 // Field scala/collection/immutable/Nil$.MODULE$:Lscala/collection/immutable/Nil$;
      69: invokespecial #97                 // Method scala/collection/immutable/$colon$colon."<init>":(Ljava/lang/Object;Lscala/collection/immutable/List;)V
      72: astore        4
      74: aload         4
      76: astore        5
      78: aload_1
      79: invokevirtual #100                // Method scala/collection/immutable/List.tail:()Ljava/lang/Object;
      82: checkcast     #80                 // class scala/collection/immutable/List
      85: astore        6
      87: aload         6
      89: getstatic     #76                 // Field scala/collection/immutable/Nil$.MODULE$:Lscala/collection/immutable/Nil$;
      92: if_acmpeq     145
      95: new           #78                 // class scala/collection/immutable/$colon$colon
      98: dup
      99: aload         6
     101: invokevirtual #84                 // Method scala/collection/immutable/List.head:()Ljava/lang/Object;
     104: invokestatic  #90                 // Method scala/runtime/BoxesRunTime.unboxToInt:(Ljava/lang/Object;)I
     107: invokestatic  #49                 // Method $anonfun$simple$1:(I)I
     110: invokestatic  #94                 // Method scala/runtime/BoxesRunTime.boxToInteger:(I)Ljava/lang/Integer;
     113: getstatic     #76                 // Field scala/collection/immutable/Nil$.MODULE$:Lscala/collection/immutable/Nil$;
     116: invokespecial #97                 // Method scala/collection/immutable/$colon$colon."<init>":(Ljava/lang/Object;Lscala/collection/immutable/List;)V
     119: astore        7
     121: aload         5
     123: aload         7
     125: invokevirtual #104                // Method scala/collection/immutable/$colon$colon.tl_$eq:(Lscala/collection/immutable/List;)V
     128: aload         7
     130: astore        5
     132: aload         6
     134: invokevirtual #100                // Method scala/collection/immutable/List.tail:()Ljava/lang/Object;
     137: checkcast     #80                 // class scala/collection/immutable/List
     140: astore        6
     142: goto          87
     145: aload         4
     147: astore        8
     149: goto          160
     152: aload_1
     153: aload_2
     154: aload_3
     155: invokestatic  #110                // InterfaceMethod scala/collection/TraversableLike.map$:(Lscala/collection/TraversableLike;Lscala/Function1;Lscala/collection/generic/CanBuildFrom;)Ljava/lang/Object;
     158: astore        8
     160: aload         8
     162: checkcast     #80                 // class scala/collection/immutable/List
     165: areturn

  public static final int $anonfun$simple$1(int);
    Code:
       0: iload_0
       1: iconst_1
       2: iadd
       3: ireturn
}